Question of world interest? (3)
I believe the answer is:
who
'question' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for who that I've seen before include "Question of identity" , "Universal health body" , "medical experts" , "The - - , rock legends" , "Fictional doctor" .)